2 year old hit newborn

Guys I need help. Not sure how to handle this. I have a 2 year old and a 2 week old. My oldest had been getting very clingy for weeks before I gave birth and has been worse since. Today my newborn was crying and my 2 yr old was also calling for me. I picked up the newborn to change her diaper and my daughter came over and sat down and tried to kick the baby on her head. I told her firmly no that we don’t kick the baby. She kept trying and then tried smacking her with her hand. I picked up the baby and moved to her back to her bassinet where my daughter can’t reach. How do I fix this before it gets any worse?